CVE-2026-33773: An Incorrect Initialization of Resource vulnerability in the packet forwarding engine (pfe) of Juniper Network

Routine

MEDIUM 5.8REMOTEMITIGATE

CVE-2026-33773 is a medium-severity flaw (CVSS 5.8) affecting junos. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An Incorrect Initialization of Resource vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on specific EX Series and QFX Series device allows an unauthenticated, network-based attacker to cause an integrity impact to downstream networks. When the same family inet or inet6 filter is applied on an IRB interface and on a physical interface as egress filter on EX4100, EX4400, EX4650 and QFX5120 devices, only one of the

Why this priority

Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.8 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.2% (top 90%)
CISA exploited list	No
Published	2026-04-09
Last modified	2026-10-26

Publisher (CNA): Juniper Networks, Inc. · Vendor: juniper

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-09 22:16 UTCPublished CVE record published
2026-10-26 22:10 UTCUpdated Record last modified

juniper junos MITIGATE

Affected: 23.4 r2-s6 · 24.2 r2-s3

Fixed in: no fixed release known

Safe to downgrade to: a release before 23.4

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-33773?

junos: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-33773 being exploited?

CVE-2026-33773 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-33773 affect?

CVE-2026-33773 affects junos. Severity is medium (CVSS 5.8). An Incorrect Initialization of Resource vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on specific EX Series and QFX Series device allows an unauthenticated, network-based attacker to cause an integrity imp

How urgent is CVE-2026-33773?

Priority 28/100. Remotely exploitable, no login, no user action

Software pages

Juniper Junos vulnerabilities

Related CVEs

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References

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